Term third estate Definition: In past centuries, this included the peasants, serfs, or slaves who performed the dirty deeds for the ruling elite. In modern times, this is the workers, taxpayers, and consumers who have limited ownership of and control over resources usually nothing more than their own labor. The third estate, which forms the backbone of any modern economy, is usually at odds with the business leaders of the second estate. Help may come from the government leaders of the first estate or the journalist of the fourth estate--but don't count on it.